A 16-year-old boy was seriously injured Saturday after a car struck him while he was riding his bicycle on Route 6 near a Cumberland Farms store in Wellfleet, police said. According to a press release, police responding to the scene at 12:37 p.m. found the teen was “not breathing and unresponsive,” and CPR was performed by responders until Wellfleet firefighters arrived. The teen was first flown to Cape Cod Hospital in Hyannis, then to Beth Israel Deaconess Medical Center in Boston, the release said. Police last night said they were not aware of his condition.